Repeat alarm with condition indicator



March 14, 1967 C(ABALCHUNAS 3,308,617

REPEAT ALARM WITH CONDITION INDICATOR 1 Filed June 15, 1965 2 Sheets-Sheet l 86 4 FIG. 3

76 85 INVENTOR.

CHARLES. A. BALCHUNAS ATTORNEY March 1967 c. A. BALCHUNAS 3,

REPEAT ALARM WITH CONDITION INDICATOR Filed June 15, 1965 2 Sheets-Sheet 2 I FIG. 4

' FIG. 5

38 7e 7e 2| 2o 22 I 7e I 86 2% 32 3o 80 l 44 i 70 72 34 ..Ll' 42 L3 5 24 54 I I 92 4O 26 24 26 l4 l2 4 a4 9 94 36 48 4e 2 2? 85 as 28 maam 86 INTOR. CHARLES A. BALCHUNAS 285; BY Z W ATTORNEY 3,308,617 REPEAT ALARM WITH CONDITION INDICATOR Charles A. Balchunas, Hopkinton, Mass., assignor to General Electric Company, a corporation of New York Filed June 15, 1965, Ser. No. 464,080 9 Claims. (Cl. 5821.155)

This invention relates to a mechanism for a repeat alarm and, more particularly, to a temporary shut-off mechanism for a timer-operated radio.

Repeat alarms are now well known to the horological art. Such alarms are generally designed to be activated at a preselected time which has been set by the user. Upon being awakened, a temporary shut-off mechanism may be actuated which causes the alarm to be shut off for a short period of time which is normally built into the mechanism. This provides an additional short sleep period after which the alarm sounds once more to pre' vent the user from oversleeping.

One of the disadvantages of repeat alarms known to the prior art is that it is not possible to tell by visual inspection whether or not the repeat mechanism is engaged. This is normally controlled by a lever which is depressed by the user to shut off the alarm and start the repeat mechanism. However, the lever does not remain depressed but returns to its original position. For this reason, an observer cannot tell whether the alarm has not yet been actuated or whether it is in the process of repeating.

Still another disadvantage of prior art repeat alarms is that the mechanisms are relatively complex. For example, several elements may be required for the actuating lever alone, increasing the frictional drag and making it more difiicult to manipulate than would be desirable.

Accordingly, it is a primary object of the present invention to provide an improved repeat alarm mechanism.

Another object is to provide a repeat alarm mechanism wherein the actuating lever remains depressed throughout the alarm repeat period.

Another object is to provide a repeat alarm mechanism wherein the frictional drag on the actuating lever is reduced.

Another object is to provide a repeat alarm mechanism of simple and eeconomical construction.

In accordance with one aspect of the invention, a sectorial cam is positioned adjacent the minute hand gear of a timer. The cam is rotatable coaxial with the minute hand gear and is also radially movable relative to the gear. A tab projecting fromthe cam is engageable with the gear when the cam is moved radially inward. A cam spring urges the cam in a first direction of rotation. A manually operable actuating level normally engages the cam and keeps it rotationally retracted against the force of its spring. When the alarm sounds, the lever may be depressed, thereby stopping the alarm and releasing the cam. The cam engages the minute hand gear which begins to drive it back to its original position. The cam meanwhile keeps the lever depressed. A leaf spring connected to the lever biases it against the cam, keeping the cam engaged with the gear. The same leaf spring serves both to hold and guide the lever and also serves as a substantially frictionless pivot.

Further objects and advantages of the invention will become apparent from the following description, the appended claims, -and the figures of the accompanying drawings wherein:

FIG. 1 is a partial perspective view of a repeat mechanism constructed in accordance with the invention, the front plate and certain other elements being removed to more fully disclose its construction;

United States Patent 3,308,617 Patented Mar. 14, 1967 showing the repeat the repeat mechanism engaged.

In the embodiment described herein, the repeat mechanism is described as applied to a clock radio without a separate alarm. However, such description is for purposes of illustration only and it will be readily apparent to those skilled in the art that the basic features of this invention may be applied to other types of mechanisms.

With particular reference to the drawings, there is illustrated a timer mechanism supported by a framework including a back plate 10 and a front plate 12 which are interconnected in spaced relationship by means of spacer posts 14. An electric clock motor 16 is mounted on the back plate 10 and drives the timer mechanism by means of a drive pinion 18. The drive pinion 18 actuates a gear train 20 which is conventional and includes a second hand gear 21, a minute hand gear 22, and an hour hand gear 24. The gear train 20 controls the various shafts of a shaft stack 28 to which are connected the hands (not shown) of a standard clock dial. An alarm gear 26 is mounted adjacent front plate 12 on the inner end of an alarm hand shaft 27 which forms the outer element of stack 28. The hour hand gear 24 includes a forwardfacing cam 24' and the alarm gear 26 includes a rearwardfacing cam 26'. The cams 24', 26' are designed to engage in the usual manner to displace hour hand gear 24 to the rear at the alarm time.

As mentioned above, the timer of this invention is described herein as applied to a clock radio. The radio is controlled by means of a switch, comprising a re siliently movable switch arm 30 carrying at its free end a pair of opposed switch contacts 32. Thesecontacts are positioned within a U-shaped stationary terminal 34 so that a circuit may be completed by the switch arm when it is in either of two extreme positions. The normal resiliency of the switch arm 30 biases the contact 32 in a direction toward the gear train so that the switch normally tends to remain closed as illustrated in FIG. 2.

The switch is controlled by means of a switch actuating member 36 which is formed from a sheet of insulating material. The configuration of member 36 is best illustrated in FIGS. 4, 5 and 6. The member 36 includes an inwardly extending projection 38, a notch 40, including a shoulder 42, to the left of projection 38, and an inwardly projecting tab 44 at the extreme left end of member 36. The front edge of switch actuating member 36 I defines a pawl 46 which, as shown in FIG. 4, may engage the edge of opening 48 in front plate 12. The extreme right end of switch actuating member 36 carries an elongated finger 50, which bears against the back surface of the hour hand gear 24. The switch actuating member 36 has limited movement within its major plane. This is permitted, and the member is positioned, by mounting it within slots defined by an insulating housing around the switch members 30, 34. This housing is not illustrated in order to simplify the showing. The right hand end of the switch actuating member 36 is given an outward bias by means of a wire spring 52 which has one end hooked through an opening 54 in member 36 and the other through an opening 56 in back plate 10.

Mounted on the minute hand shaft 58 of gear train 20 is an alarm repeat cam 60. The cam is generally sectorial in shape with an elongated shaft-receiving aperture 62 near the small end of the sector. The circumferential portion of'the cam has two levels-a level 64 of shorter radius which occupies much of the length of the circumferential portion and terminates at one end in a toe 66 and a second level 68 of longest radius near the other edge of the sector. The two levels are joined by a shoulder 69. The radial edge which lies along the side of greatest radial length has a projection 70 which retains one end of a spring 72. The spring 72 includes a central clip portion which engages an annular slot in the minute hand shaft 58 to retain the cam 60 axia-lly positioned along the shaft. The end of the spring opposite the projection 70 bears against a groove 14' in one of the spacer posts 14 so that the cam is urged in a counterclockwise direction, as viewed in FIGS. 1, 2, and 3. The force exerted by spring 72 also urges the cam outwardly along its elongated aperture as shown in FIG. 2. An inwardly bent tab 74 extends rearwardly from the plane of the cam and past the plane of the minute hand gear 22. Slidably mounted between the back plate and the clock motor 16 is an actuating lever 76. The lever includes a slot 77 providing clearance around the exposed rearward end 14a of one of spacer posts 14. The lever also includes a guide slot (not shown) which is slidable on a bushing surrounding the motor shaft carrying drive pinion 18. The innermost end of the lever 76 is bent forwardly through an opening 78 in back plate 10. The end projection 76' extends forwardly, as shown in FIG. 4, adjacent the projection 38 of switch actuating member 36. A cam engaging finger 80 extends forwardly from the end projection 76' in a plane which is perpendicular to the end projection. The opposite end 82 of the actuating lever 76 extends outside the timer case for manual actuation. A leaf spring 84, which is secured to the front plate by a rivet 85, is slotted to engage a pair of opposed cutouts 86 in the actuating lever. Spring 84 exerts an outward force, tending to retract the lever 76 to the right, as viewed in the drawings. In addition, the width of spring 84 is sufficient to make it relatively immovable except for rotation about its bent portion 84'. Thus, the spring serves the multiple function of a friction pivot, a holder, and a guide for the lever 7 6. To the extreme left end of the mechanism and extending between plates 10 and 12, there is mounted a three position selector switch 88. The switch includes an arm 90 which is arranged to engage the tab 44 of switch actuating member 36. Another arm 92 includes a detent which engages one of three depressions 94 on the inner surface of front plate 12, under the influence of spring 96.

Operation The operation of the timer mechanism of this invention may best be understood by reference to the sequential illustrations of FIGS. 4, 5, and 6 and by further reference to FIGS. 2 and 3. FIG. 4 illustrates the mechanism in the position in which it will be found when the radio is off but selector switch 88 is set for automatic operation and the alarm time has not yet been reached. Under these conditions, it will be noted that the cam 24' of the hour hand gear 24 has not yet contacted the cam 26' of the alarm gear 26. Under these conditions, the spring 52 forces the switch actuating member 36 outwardly so that the pawl 46 engages the edge of the opening 48 in front plate 12. At the same time, the shoulder 42 bears against the switch arm 30, maintaining the switch intermediate the U of terminal 34 in the open position, while the resiliency of the switch arm serves to retain the pawl 46 within the opening. The selector switch 88 is shown rotated-to its clockwise position, permitting normal operation of the radio alarm. While the actuating member 36 is in the position illustrated in FIG. 4, the repeat cam 60 is positioned as illustrated in FIG. 2. The toe 66 of the cam rests against the finger 80. This holds the cam against the force of spring 72. Spring 72 also serves to force the cam outwardly along its aperture 62 to maintain tab 74 out of engagement with the teeth of minute hand gear 22.

As the alarm time approaches, hour hand gear 24 continues to rotate and the hour hand gear cam 24' begins to ride up onto the alarm gear cam 26'. Gear 24 is forced inwardly, as shown in FIG. 5, forcing the finger 50 inward and releasing the pawl 46 from its engagement within opening-48. The resiliency of the switch arm 30 then forces the switch actuating member 36 to the right and into the position shown in FIG. 5, allowing the switch to close. This then permits the radio to come on. The position of the mechanism at this stage is further shown in FIG. 2.

Upon being awakened, the user of the alarm may now desire a further short period of sleep. He thereupon depresses the end 82 of the actuating lever 76, sliding the lever to the left. The finger at the end of the lever releases the toe 66 of cam 60 and the stored energy within spring 72 pivots the cam counterclockwise until the shoulder 69 abuts against the finger 80, as shown in FIG. 3. Upon removing finger pressure from the end 82 of actuating lever 76, the leaf spring 84 tends to force the lever outwardly. The finger 80, bearing against the short radius level 64 of cam 60, forces the cam to slide inwardly on its elongated aperture 62 until the tab 74 engages the teeth of minute hand gear 22, as shown in FIG. 3. However, it will be noted that the lever 76 is not allowed to return to its original position, inasmuch as its return is obstructed by the short radius edge 64 of cam 60. Therefore, during the repeat period, the lever remains depressed. Furthermore, it will be seen in FIG. 6 that as a result of the leftward movement of lever 76, pro-j jection 76 of the actuating lever has moved the projection 38 of switch actuating member 36 to its retracted position so that the shoulder 42 has moved the switch arm 30 to a position intermediate the U of terminal 34 in an open switch position, thun turning the radio off.

The minute hand gear 22 continues to rotate in a clockwise direction as viewed in FIG. 3. As this rotation continues, the cam tab 74, which is engaged with the teeth of the minute hand gear, is carried along with the minute hand gear so that the cam 60 rotates in a clockwise direction. This rotation continues until the finger 80' reaches the drop off at toe 66, whereupon the actuating lever 76 is released. The leaf spring 84 forces it back to its rightward outer most position, releasing the switch actuating member 36 and permitting the switch to close. The radio thereupon comes on once again. The user may now leave the radio on or manually turn the selector switch 88 to its central, or off position. The latter action causes the arm 90 to contact tab 44 and retract the switch actuating member 36 to the left, forcing switch arm 30 to its intermediate open position. As soon as the cams 24', 26 become disengaged, the pawl 46 is free to reenter opening 48, under the influence of spring 52, returning the mechanism to its original condition.

As is common with clock-radio controls, at any time the radio may be manually turned on by rotating select-or switch 88 to its full left position. This closes the switch to the left by causing the left contact 32 to engage the left leg of the U of terminal 34.

It will now be apparent to those skilled in the art that the present invention achieves all the objectives heretofore set forth. It will also be apparent that a number of variations and modifications may be made in this inven* tion. Accordingly, the foregoing description is intended to be illustrative only, rather than limiting. The pur pose of the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of'the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A temporary shut-off mechanism which comprises: a timer; a gear rotatable by said timer; an alarm actuat ing arm normally biased to an alarm position but movable to a silent position; an actuating member movable between a first position urging said arm to said silent position and a second position released from said arm, permitting it to move to said alarm position; latch means normally retaining said actuating member in said first position; release means for disengaging said actuating member from said latch means at an alarm time; cam means coaxially mounted relative to said gear for rotation between first and second arcuate positions and for motion between outer and inner radial positions relative to said gear, said cam means including an arcuate peripheral bearing surface; means on said cam means for engaging the teeth of said gear when said cam means is in its radically inner position; resilient means normally urging said cam means to said second arcuate position and said outer radial position; manually operable lever means normally retaining said cam means in its first arcuate position but shiftable to release said cam means and simultaneously force said actuating member to its first position, said lever means thereafter being retained against said actuating member by the peripheral bearing surface of said cam means to enable an observer to tell that the temporary shut-off mechanism is engaged; and spring means biasing said lever means to move said cam means to its radially inner position to cause said engaging means to engage said gear teeth, whereby said cam means is driven by said gear and returned to its first arcuate position.

2. A temporary shut-off mechanism which comprises:

a timer; a gear rotatable by said timer; a switch arm normally biased to a closed position but movable to an open position; an actuating member movable between a first position urging said switch arm to said open position and a second position released from said switch arm, permitting it to move to said closed position; latch means normally retaining said actuating member in said first position; release means for disengaging said actuating mem-' her from said latch means at an alarm time; cam means coaxially mounted relative to said gear for rotation between first and second arcuate positions and for motion between outer and inner radial positions relative to said gear, said cam means including an arcuate peripheral bearing surface; means on said cam means for engaging the teeth of said gear when said cam means is in its radially inner position; resilient means normally urging said cam means to said second arcuate position and said outer radial position; manually operable lever means normally retaining said cam means in its first arcuate position but shiftable to release said cam means and simultaneously force said actuating member to its first position, said lever means thereafter being retained against said actuating member by the peripheral bearing surface of said cam means to enable an observer to tell that the temporary shut-off mechanism is engaged; and spring means biasing said lever means to move said cam means to its radially inner position to cause said engaging means to engage said gear teeth, whereby said cam means is driven by said gear and returned to its first arcuate position.

3. A temporary shut-off mechanism which comprises: a timer; a gear rotatable by said timer; an alarm actuating arm normally biased to an alarm position but movable to a silent position; an actuating member movable between a first position urging said arm to said silent position and a second position released from said arm, permitting it to move to said alarm position; latch means normally retaining said actuating member in said first position; release means for disengaging said actuating member from said latch means at an alarm time; cam means coaxially mounted relative to said gear for rotation between first and second arcuate positions and for motion between outer and inner radial positions relative to said gear, said cam means including an arcuate peripheral bearing surface terminating in a toe portion at one end and a radially extending shoulder at the other end; means on said cam means for engaging the teeth of said gear when said cam means is in its radially inner position; resilient means normally urging said cam means to said second arcuate position and said outer radial position; manually operable lever means having an offset finger normally contacting said toe portion to retain said cam means in its first arcuate position but shiftable to release said toe portion and engage said shoulder and simultaneously force said actuating member to its first position, said lever means thereafter being retained against said actuating member by the peripheral bearing surface of said cam means to enable an observer to tell that the temporary shut-off mechanism is engaged; and spring means biasing said lever means and finger to move said cam means to its radially inner position to cause said engaging means to engage said gear teeth, whereby said cam means is driven by said gear and returned to its first arcuate position, said finger thereupon reengaging said toe portion.

4. A temporary shut-off mechanism which comprises: a timer; a minute hand gear rotatable by said timer; an alarm actuating arm normally biased to an alarm position but movable to a silent position; an'actuating member movable between a first position urging said arm to said silent position and a second position-released from said arm, permitting it to move to said alarm position; latch means normally retaining said actuating member in said first position; release means for disengaging said actuating member from said latch means at an alarm time; cam means defining an elongated shaft opening for coaxially mounting said cam means on a common shaft with said gear for rotation between first and second arcuate position and for motion between outer and inner radial positions relative to said gear, said cam means including an arcuate peripheral bearing surface; tab means on said cam means for engaging the teeth of said gear when said cam means is in its radially inner position; resilient means normally urging said cam means to said second arcuate position and said outer radial position; manually operable lever means normally retaining said cam means in its first arcuate position but shiftable to release said cam means and simultaneously force said actuating member to its first position, said lever means thereafter being retained against said actuating member by the peripheral bearing surface of said cam means to enable an observer to tell that the temporary shut-otf mechanism is engaged; and spring means biasing said lever means to move said cam means to its radially inner position to cause said tab means to engage said gear teeth, whereby said cam means is driven by said gear and returned to its first arcuate position.

5. A temporary shut-off mechanism which comprises: a framework; a timer mounted on said framework; a gear rotatable by said timer; an alarm actuating arm normally biased to an alarm position but movable to a silent position; an actuating member movable between a first position urging said arm to said silent position and a second position released from said arm, permitting it to move to said alarm position; latch means normally retaining said actuating member in said first position; release means for disengaging said actuating member from said latch means at an alarm time; cam means coaxially mounted relative to said gear for rotation between first and second arcuate positions and for motion between outer and inner radial positions relative to said gear, said cam means including an arcuate peripheral bearing surface; means on said cam means for engaging the teeth of said gear when said cam means is in its radially innerposition; resilient means normally urging said cam means to said second arcuate position and said outer radial position; manually operable elongated lever means normally retaining said cam means in its first arcuate position but longitudinally shiftable to release said cam means and simultaneously force said actuating member to its first position, said lever means thereafter being retained against said actuating member by the peripheral bearing surface of said cam means to enable an observer to tell that the temporary shut-off mechanism is engaged; and a leaf spring having a first end secured to said framework and a second end engaging said lever means and biasing said lever means to move said cam means to its radially inner position to cause said engaging means to engage said gear teeth, whereby said cam means is driven by said gear and returned to its first arcuate position.

6. A temporary shut-off mechanism which comprises: a framework; a timer mounted on said framework; a gear rotatable by said timer; an alarm actuating arm normally biased to an alarm position but movable to a silent position; an actuating member movable between a first position urging said arm to said silent position and a second position released from said arm, permitting it to move to said alarm position; latch means normally retaining said actuating member in said first position; release means for disengaging said actuating member from said latch means at an alarm time; cam means coaxially mounted relative to said gear for rotation between first and second arcuate positions and for motion between outer and inner radial positions relative to said gear, said cam means including an arcuate peripheral bearing surface; means on said cam means for engaging the teeth of said gear when said cam means is in its radially inner position; resilient meansnormally urging said cam means to said second arcuate position and said outer radial position; manually operable elongated lever means defining a pair of opposed cutout portions in opposite edges thereof and normally retaining said'cam means in its first arcuate position but longitudinally shiftable to release said cam means and simultaneously force said actuating member to its first position, said lever means thereafter being retained against said actuating member by the peripheral bearing surface of said cam means to enable an observer to tell that the temporary shut-off mechanism is engaged; and a substantially L-shaped leaf spring having a first leg secured to said framework and a second leg substantially perpendicular to said lever, the end of said second leg terminating in a pair of spaced extensions engaging said cutout portions, said leaf spring biasing said lever means to move said cam means to its radially inner position to cause said engaging means to engage said gear, whereby said cam means is driven by said gear and returned to its first arcuate position.

7. A temporary shut-off mechanism which comprises: a framework; a timer mounted on said framework; a minute hand gear rotatable by said timer; a switch arm normally biased to a closed position but movable to an open position; an actuating member movable between a first position urging said switch arm to said open position and a second position released from said switch arm, permitting it to move to said closed position; latch means normally retaining said actuating member in said first position; release means for disengaging said actuating member from said latch means at an alarm time; cam

means defining an elongated shaft opening for coaxially mounting said cam means on a common shaft with said gear for rotation between first and second arcuate positions and for motion between outer and inner radial positions relative to said gear, said cam means including an arcuate peripheral bearing surface terminating in a toe portion at one end and a radially extending shoulder at the other end; tab means on said cam means for engaging the teeth of said gear when said cam means is in its radially inner position; resilient means normally urging said cam means to said second arcuate position and said outer radial position; manually operable elongated lever means having an offset finger normally contacting said toe portion to retain said cam means in its first arcuate position but longitudinally shiftable to release said toe portion and engage said shoulder and simultaneously force said actuating member to its first position, said lever means thereafter being retained against said actuating member by the peripheral bearing surface of said cam means to enable an observer to tell that the temporary shut-off mechanism is engaged; and spring means biasing said lever means to move said cam means to its radially inner position to cause said tab means to engage said gear teeth, whereby said cam means is driven by said gear and returned to its first arcuate position.

8. A temporary shut-off mechanism which comprises: a framework; a timer mounted on said framework; a minute hand gear rotatable by said timer; a switch arm normally biased to a closed position but movable to an open position; an actuating member movable between a first position urging said switch arm to said open position and a second position released from said switch arm, permitting it to move to said closed position; latch means normally retaining said actuating member in said first position; release means for disengaging said actuating member from said latch means at an alarm time; cam means defining an elongated shaft opening for coaxially mounting said cam means on a common shaft with said gear for rotation between first and second arcuate positions and for motion between outer and inner radial positions relative to said gear, said cam means including an arcuate peripheral bearing surface terminating in a toe portion at one end and a radially extending shoulder at the other end; tab means on said cam means for engaging the teeth of said gear when said cam means is in its radially inner position; resilient means normally urging said cam means to said second arcuate position and said outer radial position; manually operable elongated lever means defining a pair of opposed cutout portions in opposite edges thereof and having an offset finger normally retaining said cam means in its first arcuate positions but longitudinally shiftable to release said cam means and simultaneously force said actuating member to its first position, said lever means thereafter being retained against said actuating member by the peripheral bearing surface of said cam means to enable an observer to tell that the temporary shut-off mechanism is engaged; and a substantially L-shaped leaf spring having a first leg secured to said framework and a second leg substantially perpendicular to said lever, the end of said second leg terminating in a pair of spaced extensions engaging said cutout portions, said leaf spring biasing said lever means to move said cam means to its radially inner position to cause said tab means to engage said gear teeth, whereby said cam means is driven by said gear and returned to its first arcuate position.

9. A temporary shut-off mechanism which comprises: a front plate defining a latch opening therein; a back plate, spaced from said front plate and parallel thereto; spacer means intermediate said front and back plates; a timer including a coaxial gear train intermediate said front and back plates including a minute hand gear, an hour hand gear, and an alarm gear, said hour hand and alarm gears being adjacent and having cooperating timer cam portions to axially displace said hour hand gear relative to said alarm gear at an alarm time; a switch arm normally biased to a closed position; an actuating member movable between a first position urging said switch arm to its open position and a second position released from said switch arm; means for biasing said actuating member to its second position; pawl means on said actuating member positioned to engage said latch opening to retain said actuating member in its first position; finger means projecting from said actuating member for engagement with said hour hand gear to disengage said pawl means from said latch opening at the alarm time; an actuating projection extending from said actuating member; cam means defining an elongated shaft opening therein coaxially mounting said cam means on the common shaft with said minute hand gear for rotation between first and second arcuate positions and for motion between outer and inner radial positions, relative to said gear, said cam means including an arcuate peripheral bearing surface terminating in a toe portion at one end and a radially extending shoulder at the other end; tab means on said cam means for engaging the teeth of said minute hand gear when said cam means is in its radially inner position; resilient means normally urging said cam means to said second arcuate position and said outer radial position; manually operable elongated lever means slidably mounted relative to said back plate and including an offset portion normally contacting said toe portion to retain said cam means in its first arcuate position but longitudinally shiftable to release said cam means and engage said shoulder and simultaneous engage said actuating projection and force said actuating member to its first position; said lever means thereafter being retained against said actuating member by the peripheral bearing surface of said cam means to enable an observer to tell that the temporary shut-off mechanism is engaged; and spring means biasing said lever means against said bearing surface to move said cam means to its radially inner position to cause said tab means to engage the teeth of said minute hand gear, whereby said cam means is driven by said minute hand gear and returned to its first arcuate position, said offset portion thereupon reengaging said toe port-ion.

References Cited by the Examiner UNITED STATES PATENTS 3,152,229 10/1964 Sears 20038 References Cited by the Applicant UNITED STATES PATENTS 2,946,182 7/1960 Boyles. 2,994,183 8/ 1961 Diamond. 3,086,351 4/1963 Boyles.

RICHARD B. WILKINSON, Primary Examiner. GERALD F. BAKER, Assistant Examiner. 

1. A TEMPORARY SHUT-OFF MECHANISM WHICH COMPRISES: A TIMER; A GEAR ROTATABLE BY SAID TIMER; AN ALARM ACTUATING ARM NORMALLY BIASED TO AN ALARM POSITION BUT MOVABLE TO A SILENT POSITION; AN ACTUATING MEMBER MOVABLE BETWEEN A FIRST POSITION URGING SAID ARM TO SAID SILENT POSITION AND A SECOND POSITION RELEASED FROM SAID ARM, PERMITTING IT TO MOVE TO SAID ALARM POSITION; LATCH MEANS NORMALLY RETAINING SAID ACTUATING MEMBER IN SAID FIRST POSITION; RELEASE MEANS FOR DISENGAGING SAID ACTUATING MEMBER FROM SAID LATCH MEANS AT AN ALARM TIME; CAM MEANS COAXIALLY MOUNTED RELATIVE TO SAID GEAR FOR ROTATION BETWEEN FIRST AND SECOND ARCUATE POSITIONS AND FOR MOTION BETWEEN OUTER AND INNER RADIAL POSITIONS RELATIVE TO SAID GEAR, SAID CAM MEANS INCLUDING AN ARCUATE PERIPHERAL BEARING SURFACE; MEANS ON SAID CAM MEANS FOR ENGAGING THE TEETH OF SAID GEAR WHEN SAID CAM MEANS IS IN ITS RADIALLY INNER POSITION; RESILIENT MEANS NORMALLY URGING SAID CAM MEANS TO SAID SECOND ARCUATE POSITION AND SAID OUTER RADIAL POSITION; MANUALLY OPERABLE LEVER MEANS NORMALLY RETAINING SAID CAM MEANS IN ITS FIRST ARCUATE POSITION BUT SHIFTABLE TO RELEASE SAID CAM MEANS AND SIMULTANEOUSLY FORCE SAID ACTUATING MEMBER TO ITS FIRST POSITION, SAID LEVER MEANS THEREAFTER BEING RETAINED AGAINST SAID ACTUATING MEMBER BY THE PERIPHERAL BEARING SURFACE OF SAID CAM MEANS TO ENABLE AN OBSERVER TO TELL THAT THE TEMPORARY SHUT-OFF MECHANISM IS ENGAGED; AND SPRING MEANS BIASING SAID LEVER MEANS TO MOVE SAID CAM MEANS TO ITS RADIALLY INNER POSITION TO CAUSE SAID ENGAGING MEANS TO ENGAGE SAID GEAR TEETH, WHEREBY SAID CAM MEANS IS DRIVEN BY SAID GEAR AND RETURNED TO ITS FIRST ARCUATE POSITION. 